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有一个表里面有某个字段出现重复记录,怎样保留重复记录中的第一_MySQL

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Release: 2016-06-01 13:55:16
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有一个表里面有某个字段出现重复记录,怎样保留重复记录中的第一条记录

select   *,identity(int,1,1)   ID   into   #t1   from   table1  
  delete   a  
  from   #t1   a  
  where   ID   >   (select   min(ID)   from   #t1   where   field1=a.field1   and  
    field2=a.field2   and   ...   fieldn=a.fieldn)  
   
  trancate   table   table1  
  alter   table   #t1   drop   column   ID  
  insert   into   table1   select   *   from   #t1

也许可以这样,简便些  
  select   distinct   *   into   #t1   from   table1  
  trancate   table   table1  
  insert   into   table1   select   *   from   #t1

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